The present invention relates to an insertion guide apparatus and method of use of the guide apparatus, and particularly to an apparatus configured to align proximally a femoral prosthesis in an intramedullary canal and method of using said apparatus. More particularly, the present invention relates to an apparatus and method for forming a reference that positions a prosthesis in the intramedullary canal and using the reference to align proximally the prosthesis within the canal of the femur.
Prosthesis are often used to replace the femoral head and acetabulum of the hip in such instances of fracture or chronic arthritis. See for example the pamphlet entitled "Surgical Technique Total Hip System Endurance.TM." by DePuy Inc., 1994 and U.S. Pat. No. 5,286,260 entitled "Modular Hip Prosthesis", to Richard Bolesky. In a conventional hip replacement surgery, a femoral head is removed from a femur, a hollow cavity is drilled into the femur, and a conventional implant is cemented within the cavity. A conventional acetabular cup is also cemented in place within the acetabulum of the hip.
According to the present invention, a calcar cutter apparatus is provided for forming a reference in a resected surface of a femur. The apparatus comprises a body formed to include a first end and a second end and teeth extending from the first end. The teeth are positioned to be in a pre-determined pattern to form a reference in a femur. Preferably, the teeth are positioned to lie in a row in the shape of ring. In addition, the teeth may be positioned to lie in a spaced-apart relationship relative to one another and channels may be positioned to lie between the teeth. A secondary tooth may also extend from each tooth.
According to another embodiment of the invention, an apparatus is provided for aligning a femoral implant within a femur having a canal and a reference formed in the femur spaced apart from the canal. The apparatus includes a handle and a clamp coupled to the handle. The clamp includes jaws adapted to engage the implant and an extension extending from at least one of the jaws. The extension is adapted to be received within the reference to align the implant within the canal. Preferably, the extension includes outer and inner surfaces and a rim that extends between the surfaces and is adapted to be received in the reference of the femur.
In addition, a kit is provided for centering proximally an implant within a canal formed in a femur. The kit includes a calcar cutter adapted to form a reference in a resected surface of the femur and a guide adapted to support the implant. The guide is also formed for extension into the reference to align the implant within the canal. Preferably, the calcar cutter includes a body having teeth extending from the body. The teeth lie in a pre-determined series relative to one another spaced-apart from the perimeter of the body. The guide includes a handle and a clamp coupled to the handle. The handle has jaws adapted to engage selectively the implant and an extension extending from one of the jaws. The extension is adapted to be received within the reference to align the implant within the canal.
A method for aligning proximally an implant within a canal of a femur is also provided in accordance with the present invention. The method includes the steps of forming a reference in a resected surface of the femur, providing an alignment insertion guide for holding an implant, positioning at least a portion of the guide in the reference so that the implant extends into the canal of the femur in a pre-determined aligned position.
Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.